A) Field of the Invention
The present invention relates to optical transmission path forming techniques using optical fibers, and more particularly to an optical fiber array, and an optical fiber fixing plate to be used for manufacturing an optical fiber array.
B) Description of the Related Art
Conventionally, two-dimensional optical fiber arrays have already been suggested by the same applicant of the present invention such as shown in FIGS. 45 and 46 (for example, refer to the JP-A 2001-241180).
The optical fiber arrays shown in FIGS. 45 and 46 have holding holes J1 to J8 that penetrate from one end surface of an optical fiber holder 1 to another end surface. Also, at the end surface of the holder 1, a positioning plate 2 that has positioning holes H1 to H8 corresponding to the holding holes J1 to J8 is attached. Optical fibers F1 to F8 are pierced from the holding holes J1 to J8 in a condition of being equipped with the positioning plate 2 and fixed by piercing through the positioning holes H1 to H8. According to this type of optical fiber arrays, the positioning plate 2 can be formed easily and precisely, and positioning with high precision is possible.
According to the above-described conventional technique, a metallic positioning plate 2 is equipped onto a surface of the end of the holder 1.
When the positioning plate 2 is attached on the surface of the end of the holder 1, it is necessary to position a positioning hole corresponding to each holding hole precisely at micron level, and the positioning is not easy. If the positioning is not sufficient, the optical fiber may be broken during insertion.
Since the positioning plate 2 is very thin in thickness such as about 100 μm, it is difficult to hold the positioning plate 2 by its four side surfaces. Then, when the positioning plate 2 is equipped onto the surface of the end of the holder 1, it is normal that a main surface on the holder 1 side of the positioning plate 2 is adhered on the surface of the end of the holder 1 of the positioning plate 2 with an adhesive in order to be fixed. In this case, the operation to adhere the main surface of the end of the holder side 1 of the positioning plate 2 on the surface of the end of the holder 1 is not easy. If planes are not enough parallel, the adhesive layer will be uneven, and trouble such as curving of the positioning plate 2 and the like occurs at a time of heat expansion.
After attaching the positioning plate 2 on the surface of the end of the holder 1, each optical fiber is pierced to each positioning hole such as H1 and the like via each holding hole such as J1 and the like, and the optical fiber is fixed by plating process that fills up metal between each positioning hole and the optical fiber. Then, after cutting the optical fiber that is projected from the front surface of the positioning plate 2, the front surface of the positioning plate 2 is polished for planarization. Since mechanical strength of the positioning plate 2 is weaken in a fiber penetrating part to which a multiplicity of the positioning holes are configured, it is injected backward or bumped forward during the polishing process. Then, throb is caused, and sufficient planarity may not be obtained.